SANAA, Yemen -- Yemeni authorities have uncovered at least 13 al-Qaida plots to target foreign diplomats, embassies and senior military and government officials in the capital of Sanaa and other cities, a high ranking security official said Sunday.The official says authorities were tipped off by captured al-Qaida members. He says they gave information about sleeper cells plotting a string of assassinations, bombings and abductions of foreign diplomats in the capital, as well as cities in troubled southern Yemen.